Fortune Summoners: Secret of the Elemental Stone

I'm at the part of the game where they've just given me control of Stella. And I find she's really hard to use against the enemies. Especially the ones that jump and kick alot. Any tips on what to do with her?

Also, I'm at the part of the game where I'm supposed to go though a gate that has a diamond symbol on it. Apparently I was supposed to open that gate when I was playing as Arche. But I didn't. Is it still possible for me to go in that way, or do I have to go all the way back to the weather tower?

It may sound odd for an offensive mage, but block often and use fire wall a lot, it works extremely well for those melee monsters, also, if you get close and use your x + ^ they can't jump over it most of the time. As for where you're supposed to go, I'd have to check, though going back to Weathervane tower will probably work.

Alright, so after trying the game again, I've learned that it's Impossible to return to the Weathervane tower as Stella. You have to push a box to get up there and she can't push a box. And since there is absolutely no way to activate the Diamond Lever with Stella that I know of, I do believe I am completely stuck in this game right now.

Yeah, it seems you're stuck, you can go to the Carpe Fulgur (the localization teams') forums and ask there, you'll probably get more of a response, though if all else fails, make a new game file, having beaten it, I'll tell you right away that it's definitely worth it.